Param: Transition to Cycles for relevant parameters

This patch is a first step to using Cycles as a parameter type. The
main affected modules are the CPUs and the Ruby caches. There are
definitely plenty more places that are affected, but this patch serves
as a starting point to making the transition.

An important part of this patch is to actually enable parameters to be
specified as Param.Cycles which involves some changes to params.py.

src/mem/cache/BaseCache.py

@@ -37,7 +37,7 @@ class BaseCache(MemObject):
     assoc = Param.Int("associativity")
     block_size = Param.Int("block size in bytes")
     latency = Param.Latency("Latency")
-    hash_delay = Param.Int(1, "time in cycles of hash access")
+    hash_delay = Param.Cycles(1, "time in cycles of hash access")
     max_miss_count = Param.Counter(0,
         "number of misses to handle before calling exit")
     mshrs = Param.Int("number of MSHRs (max outstanding requests)")

src/mem/cache/tags/iic.cc

@@ -250,6 +250,8 @@ IIC::accessBlock(Addr addr, int &lat, int context_src)
         }
 
     }
+    // @todo: is hashDelay is really cycles, then
+    // multiply with period
     set_lat = set_lat * hashDelay + hitLatency;
     if (tag_ptr != NULL) {
         // IIC replacement: if this is not the first element of

src/mem/cache/tags/iic.hh

@@ -196,7 +196,7 @@ class IIC : public BaseTags
     const unsigned subMask;
 
     /** The latency of a hash lookup. */
-    const unsigned hashDelay;
+    const Cycles hashDelay;
     /** The total number of tags in primary and secondary. */
     const unsigned numTags;
     /** The number of tags in the secondary tag store. */